Survival to hospital discharge and neurological outcomes with targeted temperature management after in-hospital cardiac arrest: a systematic review and meta-analysis

Abstract

Background: Multiple randomized controlled trials have shown that targeted temperature management (TTM) has favorable effects in out-of-hospital cardiac arrest. However, the benefit of TTM in patients with in-hospital cardiac arrest (IHCA) remains to be verified. Methods:The PubMed, Cochrane Library, and EMBASE databases were searched for clinical studies with the primary outcomes of survival to hospital discharge and neurological outcomes. Neurological outcomes were evaluated by the categorical scale of cerebral function (CPC); a score of 1-2 points was considered neurologically good, and a score of 3-5 points was considered a poor outcome. Revman 5.3 and Stata 14 software with the random effects model were used for analysis. P<0.05 was considered statistically significant.Results: Six retrospective controlled studies with a total of 14,607 patients (TTM group: 1,845, control group: 12,762) were included and analyzed. There were no statistically significant differences between the two groups in survival to hospital discharge [odds ratio (OR) =1.02, 95% CI: 0.77-1.35, P=0.89, I 2 =47%] or favorable neurological outcomes (OR =1.06, 95% CI: 0.56-2.02, P=0.85, I 2 =79%). After excluding patients with non-shockable initial rhythms, TTM did not show any significant improvement in survival to hospital discharge. Subgroup analysis was performed according to the sample size. No significant improvement was observed between the two groups in terms of survival to hospital discharge or neurological outcome.Discussion: In this meta-analysis, the effects of TTM on discharge survival and neurological prognosis were evaluated by studying the results of IHCA in 14,607 patients. We found that the TTM did not improve survival and neurological function in discharged patients. Our results showed that the sample size discrepancy had a large effect on the heterogeneity; to address this, subgroup analyses were performed according to the different sample sizes. However, TTM treatment in different sample size subgroups showed no significant effect on survival to hospital discharge. Moreover, in the large sample size subgroup, therapeutic hypothermia was associated with increased unfavorable neurological outcome compared with no hypothermia.

Therapeutic Hypothermia Following Cardiopulmonary Arrest: A Systematic Review and Meta-Analysis with Trial Sequential Analysis

“…Whether therapeutic hypothermia improves survival is controversial, especially if neurologic outcome is not favorable. Our results are similar to previous meta-analyses that demonstrated no survival benefit with hypothermia [ 18 – 23 , 27 ]. In parallel with the analysis by Sanfilippo and colleagues, our TSA confirmed the futility of further randomized controlled trials in respect to the mortality outcome [ 22 ].…”

“…Clinically, favorable neurologic outcome is defined by the mRS or CPC scores, which describe the functionality of a patient after suffering a neurologic injury [ 16 , 17 ]. Similar to previous meta-analyses, our meta-analysis revealed no overall neurologic benefit of therapeutic hypothermia when compared to normothermia [ 18 – 23 ]. TSA of favorable neurologic outcome demonstrated the futility of therapeutic hypothermia compared to normothermia, suggesting further randomized controlled studies should likely not be conducted with this outcome.…”

Identifying Risk Factors for Prolonged Length of Stay in Hospital and Developing Prediction Models for Patients with Cardiac Arrest Receiving Targeted Temperature Management

“…To our knowledge, no randomized trials of TTM for IHCA have been conducted. A meta-analysis that included six retrospective controlled studies revealed that TTM did not improve survival or neurological function among patients with IHCA [ 44 ]. Because the characteristics of patients with IHCA and the treatment received before, during, and after arrest may differ from those of patients with OHCA, the prognosis and LOS after TTM should be evaluated as different entities [ 37 , 43 , 45 ].…”

Temperature Control After Cardiac Arrest: A Narrative Review

“…Out-of-hospital cardiac arrest (OHCA) affects over 600,000 individuals each year in the United States and Europe, while in-hospital cardiac arrest (IHCA) affects * 300,000 people a year [1], posing a major public health challenge. Mortality remains unacceptably high, with roughly one in ten OHCA and one in four IHCA patients surviving to hospital discharge [2][3][4][5].…”

“…Out-of-hospital cardiac arrest (OHCA) affects over 600,000 individuals each year in the United States and Europe, while in-hospital cardiac arrest (IHCA) affects ~ 300,000 people a year [ 1 ], posing a major public health challenge. Mortality remains unacceptably high, with roughly one in ten OHCA and one in four IHCA patients surviving to hospital discharge [ 2 – 5 ]. Hypoxic–ischemic brain injury (HIBI) is a major contributor to outcomes after cardiac arrest (CA) [ 6 ]; the burden of HIBI is determined by both the primary ischemic injury and the secondary brain injury after reperfusion [ 7 , 8 ].…”